Field of the Invention
Embodiments of the present invention relates to the field of display technology, and in particular to an array substrate, a method for manufacturing the same and a display device.
Description of the Related Art
TFT-LCD (Thin Film Transistor-Liquid Crystal Display), as a flat panel display device, is increasingly applied in a high-performance display field because of its small size, low power consumption, no radiation and relatively low manufacturing cost and other characteristics.
A TFT-LCD device, as shown in FIG. 1a, includes an array substrate 10 and a color film substrate 20, a liquid crystal layer is provided between the array substrate 10 and the color film substrate 20. A desired display image is obtained by inputting a control signal into the array substrate 10 to control a deflection of liquid crystal layer in order to adjust a transmittance of light through the liquid crystal layer.
As shown in FIG. 1b, the array substrate 10 may comprise a plurality of data lines 101 arranged in a longitudinal sequence within a display area A. In order to detect defects such as a short-circuit defect which may appear during manufacturing the array substrate 10, lead wires 112 connected with the data lines 101 are provided in a peripheral area of the display area A (non-display area). A detecting signal is input into a data line 101 via the lead wire 112 to detect the short-circuit defect appearing in the data line 101. In order to simplify the manufacturing process and reduce a resistance between the lead wires 112 and the data lines 101, typically, the lead wire 112 may be formed from a material which forms a source-drain metal layer and the data lines 101.
Further, in order to simplify the manufacturing process, during manufacturing the above array substrate 10, a pattern of the data lines 101, a semi-conductor active layer 102, a source 103, a drain 104 and the lead wire 112 is generally formed through a single patterning process (comprising a single exposure process, an ashing process and several etching processes) with a mask having a semipermeable membrane. Since the mask having a semipermeable membrane is capable of forming photoresists with different thicknesses, the photoresist with larger thickness will also be ashed out in its edge when ashing the photoresist with smaller thickness and thinning the photoresist with larger thickness, so that a width of the data line 101 will be reduced. However, since the semi-conductor active layer is located below the source-drain metal layer constituting the data lines 101, the semi-conductor active layer at the edge of the data line pattern will be exposed when etching the source-drain metal layer corresponding the area where the photoresist has been ashed out. As a result, an exposed semi-conductor active layer is enlarged corresponding to the reduced width of the data line. Thus, in order to meet the development trend of a narrow bezel display device, when wiring the lead wires 112 in the non-display area with a small space, if employing the above manufacturing process with the mask having a semipermeable membrane, the formed lead wires 112 cannot be wired in the small space due to the limitation of its width, otherwise, a probability of occurrence of the short-circuit defect may be increased because two adjacent lead wires 112 are too close, resulting in an adverse effect on a quality of the display device.